//模拟实现strcat 字符串连接函数
s末尾置0
#pragma warning(disable:4996)
#include<stdio.h>
#include<assert.h>
char* My_Strcat(char* arr, const char* tmp, size_t n)
{
	assert(arr && tmp);
	char* ret = arr;
	while (*arr++);
	--arr;
	while (n--)
	{
		if (!(*arr++ = *tmp++))
			return ret;
	}
	*arr = '\0';
	return ret;
}
int main()
{
	char arr[50] = "abcd";
	char tmp[] = "hh";
	size_t n;
	scanf("%u", &n);
	My_Strcat(arr, tmp, n);
	printf("%s\n", arr);
	return 0;
}